Scattering of a vector Bessel vortex beam by a charged sphere

Abstract

The interaction of a vector Bessel vortex beam (VBVB) with a charged sphere is investigated using generalized Lorenz–Mie theory (GLMT). The charges carried by the sphere are expressed by the surface conductivity σs. The incident VBVBs are expanded using a series of beam shape coefficients (BSCs), whose analytical expressions are derived using the angular spectrum decomposition method (ASDM). The expanded coefficients of the scattered fields are calculated by considering the boundary conditions on the surface of the sphere, which are different from that for the case of neutral sphere. The effects of the carried charges on the scattering, absorption, and extinction coefficients are considered, with particular emphasis on the effect of the order, polarization, and half-cone angle of the beams. Various polarizations including linear, circular, radial, azimuthal, and mixed polarizations are considered. Numerical results show that the scattering, extinction, and absorption efficiencies are very sensitive to the beam parameters including polarization, half-cone angle, and order. Thus in practice, the scattering, extinction, and absorption caused by charged particles can be enhanced or reduced by choosing proper beam parameters according to practical demand. Such results have many potential applications. For instance, it is of help to improve the quality of wireless communication by reducing the attenuation caused by charged particles. It can also improve the precision for particle sizing using phase Doppler anemometry by enhancing the scattering of charged spheres.